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sdgrid_pg.sdgrid_pg_ Class Reference

List of all members.

Public Member Functions

def __init__
def __call__

Private Attributes

 __bases__
 __doc__

Static Private Attributes

string __name__

Detailed Description

Definition at line 18 of file sdgrid_pg.py.


Constructor & Destructor Documentation

Definition at line 21 of file sdgrid_pg.py.


Member Function Documentation

def sdgrid_pg.sdgrid_pg_.__call__ (   self,
  infiles = None,
  antenna = None,
  scanlist = None,
  ifno = None,
  pollist = None,
  gridfunction = None,
  convsupport = None,
  truncate = None,
  gwidth = None,
  jwidth = None,
  weight = None,
  clipminmax = None,
  outfile = None,
  overwrite = None,
  npix = None,
  cell = None,
  center = None,
  plot = None,
  async = None 
)
SD task: gridding single dish data
  Keyword arguments:
infiles -- name of input SD dataset. can be list.
example: 'testimage.asap' 
         ['testimage1.asap','testimage2.asap']
antenna -- select data based on antenna name(s) or id(s)
default: -1
example: 0, 'DV01'
scanlist -- list of scan numbers to process
default: [] (use all scans)
example: [21,22,23,24]
ifno -- IFNO to be gridded
default: -1 (only process IFNO in the first row)
example: 1
pollist -- POLNO to be gridded
default: [] (all polarizations)
example: 1,[0,1]
gridfunction -- gridding function 
options: 'BOX' (Box-car), 'SF' (Spheroidal), 
         'GAUSS' (Gaussian), 'PB' (Primary-beam)
         'GJINC' (Gaussian*Jinc)
default: 'BOX'
example: 'SF'
    >>> gridfunction expandable parameter:
       convsupport -- convolution support for 'SF' 
   default: -1 (use default for each gridfunction)
   example: 3
       truncate -- truncattion radius of convolution kernel.
           effective only for 'GAUSS' and 'GJINC'.
   default: '-1' (use default for each gridfunction)
   example: 3, '20arcsec', '3pixel'
       gwidth -- HWHM for gaussian. Effective only for 
         'GAUSS' and 'GJINC'.
   default: '-1' (use default for each gridfunction)
   example: 3, '20arcsec', '3pixel'
       jwidth -- Width of jinc function. Effective only for 
         'GJINC'.
   default: '-1' (use default for each gridfunction)
   example: 3, '20arcsec', '3pixel'
weight -- weight type (both lower-case and upper-case are 
  acceptable)
options: 'UNIFORM',
         'TSYS'  (1/Tsys**2 weighted)
         'TINT'  (integration time weighted)
         'TINTSYS'  (Tint/Tsys**2)
default: 'UNIFORM'
clipminmax -- do min/max cliping if True
default: False
outfile -- output data name
default: '' (outfile will be set to infile+'.grid')
example: 'mydata.asap.grid'
overwrite -- overwrite option for outfile
default: False (not overwrite)
options: True, False
example: if True, existing file will be overwritten
npix -- x and y image size in pixels, symmetric for single value
default: -1 (automatically calculated from cell size and 
             the data)
example: npix=200 (equivalent to [200,200])
cell -- x and y cell size. default unit arcsec
default: '' (automatically calculated from npix if it is 
             set, otherwise '1.0arcmin')
example: cell=['0.2arcmin, 0.2arcmin']
         cell='0.2arcmin' (equivalent to example above)
         cell=12.0 (interpreted as '12.0arcsec'='0.2arcmin')
center -- grid center
default: '' (automatically calculated from the data)
example: 'J2000 13h44m00 -17d02m00'
         ['05:34:48.2', '-05.22.17.7'] (in J2000 frame)
         [1.46, -0.09] (interpreted as radian in J2000 frame)
plot -- Plot result or not
default: False (not plot)
example: if True, result will be plotted

DESCRIPTION:

The sdgrid task performs spatial gridding according to the user 
specification of spatial grid, convolution function, etc.

For grid configuration, the task supplements necessary information 
by referring input data if any of gridding parameter ('npix', 
'cell', or 'center') is not specified by the user. If 'center' is 
default value (empty string), central position of the grid will be 
set to the center of observed area, i.e. x=0.5*(xmax+xmin), 
y=0.5*(ymax+ymin). If either 'cell' or 'npix' is set, unspecified 
one will be calculated from the others. In that case, total extent of 
the grid will be set to cover all observed position. If neither 'cell' 
nor 'npix' is set, cell size will be set to 1.0 arcmin and number of 
pixel will be calculated based on that cell size.
 
Currently, only J2000 frame is supported.
 
The parameter gridfunction sets gridding function for imaging. 
Currently, the task supports 'BOX' (Box-car), 'SF' (Prolate 
Spheroidal Wave Function), 'GAUSS' (Gaussian), 'GJINC' (Gaussian*
Jinc), where Jinc(x) = J_1(pi*x/c)/(pi*x/c) with a first order 
Bessel function J_1, and 'PB' (Primary Beam, not implemented yet). 
For 'PB', correct antenna informations should be included in input 
file. 

There are four subparameters for gridfunction: convsupport, truncate, 
gwidth, and jwidth. The convsupport is an integer specifying cut-off 
radius for 'SF' in units of pixel. By default (convsupport=-1), 
the cut-off radius is set to 3 pixels. The truncate is a cut-off 
radius for 'GAUSS' or 'GJINC'. It accepts integer, float, and 
string values of numeric plus unit. Allowed units are angular 
units such as 'deg', 'arcmin', 'arcsec', and 'pixel'. Default unit 
is 'pixel' so that string without unit or numerical values (integer 
or float) will be interpreted as radius in pixel. Default value 
for truncate, which is used when negative radius is set, is 3*HWHM 
for 'GAUSS' and radius at first null for 'GJINC'. The gwidth is 
the HWHM of gaussian for 'GAUSS' and 'GJINC'. Default value is 
sqrt(log(2)) pixel for 'GAUSS' and 2.52*sqrt(log(2)) pixel for 
'GJINC'. The jwidth specifies width of the jinc function (parameter 
'c' in the definition above). Default is 1.55 pixel. Both gwidth 
jwidth allows integer, float, or string of numeric plus unit. 
Default values for gwidth and jwidth are taken from Mangum et al. 
(2007).

Boolean parameter 'plot' controls whether gridded result is plotted 
or not. If True, color map of gridded data will be shown. Pixel 
center and observed position are overlayed as blue dot and red dot, 
respectively. Currently, channel averaged value will be plotted.

Definition at line 26 of file sdgrid_pg.py.

References vla_uvfits_line_sf.verify.


Member Data Documentation

Definition at line 22 of file sdgrid_pg.py.

Definition at line 23 of file sdgrid_pg.py.

string sdgrid_pg.sdgrid_pg_.__name__ [static, private]

Definition at line 19 of file sdgrid_pg.py.


The documentation for this class was generated from the following file: